The well-being of patients with aplastic anemia (AA), genetically determined hematologic diseases, and myelodysplasia may depend upon events which arise late after treatment. The broad objective of this proposal is to reduce the late morbidity and mortality of marrow transplantation. There are three specific aims: 1) expand the role of ambulatory care by adopting methods to reduce hospitalization and cost by augmenting clinic/home care; 2) reduce the complications of transplantation by evaluating psoralen and ultraviolet A radiation (PUVA) as treatment of refractory cutaneous acute graft-versus-host disease (GVHD), documenting the pattern and etiology of early cutaneous abnormalities after transplantation, evaluating low-dose intravenous immunoglobulin (IVIg) prophylaxis in related donor transplants, evaluating the role of IVIg in preventing serious infections in unrelated donor transplants, and documenting late complications following the treatment of AA; 3)reduce the morbidity and mortality of complication, studying the efficacy of ursodeoxycholic acid (UDCA) as treatment of refractory hepatic chronic GVHD, investigating the benefit of PUVA therapy, evaluating the toxicity and efficacy of rapamycin treatment, and conducting subsequent randomized trials of promising new regimens compared with best current therapies. Investigation of the late effects of treatment is vital for the overall quality of the database of the program project and for enhancing the well-being of the marrow transplant recipient.